/* ==========================================================================
   Lò Sưởi — giao diện là đồ giấy trong phòng khách: tấm bưu thiếp có tem Đà Lạt,
   nhãn kraft, dấu sáp đỏ, nút đồng thau, thanh chương là một dây đèn nhỏ.
   Khi trời tối (--night do JS đặt), giấy ấm và tối đi theo ánh lửa.
   ========================================================================== */
:root {
  --ink: #2a1f17;
  --ink-soft: #55432f;
  --ink-faint: #8a7660;
  --pencil: #463b33;
  --paper: #f8f1e3;
  --paper-2: #efe5d1;
  --kraft: #c9a77a;
  --red: #9b2f2a;
  --red-ink: #9a2e28;
  --green: #2f5243;
  --brass: #b48a46;
  --ember: #e98a3a;
  --cream: #fff7e8;
  --tex: url('../assets/img/tex-paper.webp');
  --night: 0;
  --shadow: drop-shadow(-4px 9px 8px rgba(46, 26, 10, 0.32)) drop-shadow(-1px 2px 1.5px rgba(46, 26, 10, 0.28));
  --shadow-sm: drop-shadow(-2px 4px 3px rgba(46, 26, 10, 0.28)) drop-shadow(-0.5px 1px 0.8px rgba(46, 26, 10, 0.3));
  --lamp: brightness(calc(1 - var(--night) * 0.22)) sepia(calc(var(--night) * 0.28));
  --script: 'Ephesis', 'Dancing Script', cursive;
  --hand: 'Patrick Hand', cursive;
  --serif: 'Cormorant Garamond', 'Times New Roman', serif;
  --sans: 'Be Vietnam Pro', system-ui, sans-serif;
  --safe-b: env(safe-area-inset-bottom, 0px);
}

* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; overflow: hidden; background: #1f1a16; color: var(--ink); }
body { font-family: var(--hand); -webkit-font-smoothing: antialiased; overscroll-behavior: none; }
button { font: inherit; color: inherit; cursor: pointer; }
a { color: inherit; }
[hidden] { display: none !important; }
.defs { position: absolute; width: 0; height: 0; overflow: hidden; }

#scene { position: fixed; inset: 0; width: 100%; height: 100%; display: block; touch-action: none; outline: none; }

/* ---------- chất liệu dùng chung ---------- */
.story__card, .modal__box, .toast, .free-bar, .loader {
  background-color: var(--paper);
  background-image: var(--tex);
  background-size: 320px;
  background-blend-mode: multiply;
}
.nav-btn, .chip, .btn--light, .hover-label {
  background-color: var(--kraft);
  background-image: var(--tex);
  background-size: 260px;
  background-blend-mode: multiply;
}
.btn--primary, .nav-btn--next, .chip--red, .icon-btn[aria-pressed="true"] {
  background-color: var(--red);
  background-image: var(--tex);
  background-size: 260px;
  background-blend-mode: multiply;
}
.icon-btn svg, .nav-btn svg {
  fill: none; stroke: var(--pencil); stroke-width: 2; stroke-linecap: round; stroke-linejoin: round;
  filter: url(#pencil);
}
.w-ink {
  padding: 0.35em 0.3em 0.3em; margin: -0.35em -0.3em -0.3em;
  -webkit-mask-image: linear-gradient(90deg, #000 calc(var(--p, 1) * (100% + 1.4em) - 1.4em), transparent calc(var(--p, 1) * (100% + 1.4em)));
          mask-image: linear-gradient(90deg, #000 calc(var(--p, 1) * (100% + 1.4em) - 1.4em), transparent calc(var(--p, 1) * (100% + 1.4em)));
}

/* ---------- nút: nhãn giấy ---------- */
.btn {
  position: relative; border: 0; border-radius: 3px; padding: 0.55em 1.15em 0.5em;
  font-family: var(--hand); font-size: 1.05rem; line-height: 1.2; color: var(--ink);
  filter: var(--shadow-sm) var(--lamp);
  transition: transform 0.2s;
  transform: rotate(var(--r, -0.6deg));
}
.btn:hover { transform: rotate(var(--r, -0.6deg)) translateY(-2px); }
.btn:active { transform: rotate(var(--r, -0.6deg)) translateY(1px) scale(0.98); }
.btn:nth-child(2n) { --r: 0.8deg; }
.btn:nth-child(3n) { --r: -1.1deg; }
.btn--primary { color: var(--cream); }
.btn--ghost {
  background: transparent; color: var(--ink-soft); filter: var(--lamp);
  border: 1.5px dashed rgba(85, 67, 47, 0.45);
}
.btn--wide { width: 100%; margin-top: 0.7em; font-size: 1.15rem; }

/* ---------- nút tròn góc phải: nắp hũ ---------- */
.icon-btn {
  width: 44px; height: 44px; border-radius: 50%; display: grid; place-items: center; padding: 0;
  border: 0; background: radial-gradient(circle at 34% 28%, #f6e2b0 0 12%, #d2aa62 34%, #a57b3a 70%, #7d5a28 100%);
  box-shadow: inset 0 -2px 4px rgba(70, 40, 10, 0.45), inset 0 2px 2px rgba(255, 240, 200, 0.6), 0 0 0 2px rgba(60, 38, 16, 0.35);
  filter: var(--shadow-sm) var(--lamp);
  transition: transform 0.25s;
  transform: rotate(var(--r, 0deg));
}
.icon-btn:nth-child(1) { --r: -6deg; }
.icon-btn:nth-child(2) { --r: 4deg; }
.icon-btn:nth-child(3) { --r: -3deg; }
.icon-btn:hover { transform: rotate(var(--r)) scale(1.07); }
.icon-btn svg { width: 22px; height: 22px; }
.icon-btn svg { stroke: #3a2614; }
.icon-btn[aria-pressed="true"] svg { stroke: var(--cream); }
#btn-night .i-sun { display: none; }
#btn-night[aria-pressed="true"] .i-sun { display: block; }
#btn-night[aria-pressed="true"] .i-moon { display: none; }

/* ---------- nhãn treo ---------- */
.chip {
  --r: -2deg;
  display: inline-flex; align-items: center; gap: 0.5em; border: 0; padding: 0.38em 0.95em 0.34em 1.45em;
  font-size: 1rem; color: var(--ink);
  clip-path: polygon(11px 0, 100% 0, 100% 100%, 11px 100%, 0 50%);
  filter: var(--shadow-sm) var(--lamp);
  transform: rotate(var(--r));
  transition: transform 0.2s;
}
.chip + .chip { --r: 1.5deg; }
.chip:hover { transform: rotate(var(--r)) translateX(2px); }
.chip__dot { width: 7px; height: 7px; border-radius: 50%; flex: none; margin-left: -0.55em; background: #3b2d22; box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.5); }
.chip[aria-pressed="true"] { background-color: var(--red); color: var(--cream); }
.chip--red { color: var(--cream); }

/* ---------- màn chờ ---------- */
.loader { position: fixed; inset: 0; z-index: 50; display: grid; place-items: center; padding: 24px; color: var(--ink); text-align: center; }
.loader__inner { width: min(480px, 100%); }
.loader__kicker {
  display: inline-block; font-family: var(--sans); font-weight: 600; letter-spacing: 0.34em; text-transform: uppercase;
  font-size: 0.72rem; color: var(--green); margin: 0 0 0.6em; padding: 0.2em 0.6em; border: 2px solid currentColor;
  filter: url(#stamp); transform: rotate(-3deg);
}
.loader__names { font-family: var(--script); font-weight: 400; font-size: clamp(3.4rem, 13vw, 5.4rem); line-height: 1; margin: 0; color: var(--ink); }
.loader__names em { font-style: normal; color: var(--red); font-size: 0.75em; }
.loader__date { font-family: var(--hand); font-size: 1.35rem; letter-spacing: 0.18em; margin: 0.15em 0 0.6em; color: var(--ink-soft); }
/* ngọn lửa nhỏ trong lò */
.loader__fire { position: relative; width: 84px; height: 70px; margin: 0 auto 0.9em; }
.loader__fire b {
  position: absolute; left: 6px; right: 6px; bottom: 0; height: 12px; border-radius: 3px;
  background: repeating-linear-gradient(90deg, #6b4a33 0 22px, #4f3524 22px 26px); box-shadow: inset 0 -3px 0 rgba(0, 0, 0, 0.25);
}
.loader__fire i {
  position: absolute; bottom: 9px; left: 50%; width: 30px; height: 46px; margin-left: -15px;
  border-radius: 50% 50% 46% 46% / 62% 62% 38% 38%;
  background: radial-gradient(ellipse at 50% 78%, #fff3c2 0 16%, #ffc35a 34%, #ef7a25 62%, rgba(200, 60, 20, 0) 74%);
  transform-origin: 50% 100%; animation: flame 1.1s ease-in-out infinite alternate; mix-blend-mode: multiply;
}
.loader__fire i:nth-child(2) { width: 22px; height: 34px; margin-left: -26px; animation-duration: 0.8s; animation-delay: -0.3s; }
.loader__fire i:nth-child(3) { width: 22px; height: 30px; margin-left: 4px; animation-duration: 0.95s; animation-delay: -0.6s; }
@keyframes flame {
  0% { transform: scale(1, 1) skewX(-3deg); opacity: 0.92; }
  50% { transform: scale(0.92, 1.1) skewX(4deg); }
  100% { transform: scale(1.04, 0.94) skewX(-5deg); opacity: 1; }
}
.loader__bar { height: 3px; background: rgba(58, 42, 31, 0.12); border-radius: 2px; overflow: hidden; width: 66%; margin: 0 auto; }
.loader__bar i { display: block; height: 100%; width: 0; background: var(--red); transition: width 0.3s; }
.loader__pct { font-size: 1rem; color: var(--ink-soft); margin: 0.6em 0 0; font-variant-numeric: tabular-nums; }
.loader__intro { animation: rise 0.7s ease both; }
.loader__hello { font-family: var(--script); font-size: 2.3rem; margin: 0 0 0.2em; }
.loader__desc { font-size: 1.12rem; line-height: 1.6; color: var(--ink-soft); margin: 0 auto 1.5em; max-width: 30em; }
.loader__btns { display: flex; gap: 0.9em; justify-content: center; flex-wrap: wrap; }
.loader__btns .btn { font-size: 1.15rem; padding: 0.6em 1.4em 0.55em; }
.loader__hint { font-size: 1rem; color: var(--ink-faint); margin-top: 1.4em; }
.loader__error { color: var(--red-ink); font-size: 1.05rem; line-height: 1.6; }
@keyframes rise { from { opacity: 0; transform: translateY(10px); } }

/* ---------- góc trên ---------- */
.brand {
  position: fixed; top: 14px; left: 18px; z-index: 10; display: flex; flex-direction: column; align-items: flex-start;
  padding: 7px 14px 6px; border-radius: 2px; color: var(--ink); pointer-events: none;
  background-color: var(--paper); background-image: var(--tex); background-size: 220px; background-blend-mode: multiply;
  box-shadow: inset 0 2px 0 rgba(168, 53, 45, 0.8);
  filter: var(--shadow-sm) var(--lamp);
  transform: rotate(-1.5deg);
}
.brand__names { font-family: var(--script); font-size: 1.9rem; line-height: 1; }
.brand__names i { font-style: normal; color: var(--red); font-size: 0.62em; }
.brand__date { font-family: var(--hand); font-size: 0.85rem; letter-spacing: 0.2em; color: var(--ink-soft); padding-left: 3px; }
.tools { position: fixed; top: 18px; right: 20px; z-index: 10; display: flex; gap: 14px; }

/* ---------- thẻ kể chuyện: thẻ công thức ghim tường ---------- */
.story {
  position: fixed; z-index: 10; left: 34px; bottom: 30px; width: min(410px, calc(100vw - 68px));
  display: flex; flex-direction: column; gap: 16px;
  transition: opacity 0.45s, transform 0.45s;
}
.story.is-hidden { opacity: 0; transform: translateY(24px) rotate(-2deg); pointer-events: none; }
.story__card {
  position: relative; padding: 28px 28px 22px; border-radius: 3px;
  filter: var(--shadow) var(--lamp);
  transform-origin: 50% 0;
  /* vạch đỏ đầu thẻ + kẻ dòng xanh nhạt như thẻ ghi công thức */
  box-shadow: inset 0 3px 0 rgba(168, 53, 45, 0.85);
}
.post { position: absolute; top: -16px; right: -12px; width: 82px; height: 70px; pointer-events: none; z-index: 1; }
.post__stamp {
  position: absolute; right: 0; top: 0; width: 46px; height: 56px; padding: 4px; background: #fbf6ea;
  /* răng cưa tem: lỗ tròn chỉ ở mép (lớp lỗ tròn cộng lớp đặc phủ phần giữa) */
  -webkit-mask: radial-gradient(circle 2.3px, transparent 96%, #000) -3px -3px / 6px 6px,
                linear-gradient(#000 0 0) center / calc(100% - 6px) calc(100% - 6px) no-repeat;
          mask: radial-gradient(circle 2.3px, transparent 96%, #000) -3px -3px / 6px 6px,
                linear-gradient(#000 0 0) center / calc(100% - 6px) calc(100% - 6px) no-repeat;
  filter: drop-shadow(0 1px 1px rgba(40, 20, 6, 0.35)); transform: rotate(5deg);
}
.post__stamp svg { display: block; width: 100%; height: 100%; }
.post__mark {
  position: absolute; left: 0; top: 26px; width: 46px; height: 46px; border-radius: 50%;
  border: 1.5px solid rgba(60, 50, 70, 0.55); display: grid; place-items: center;
  font: 600 0.48rem/1 var(--sans); letter-spacing: 0.1em; color: rgba(60, 50, 70, 0.7);
  filter: url(#stamp); mix-blend-mode: multiply; transform: rotate(-12deg);
}
.post__mark::after {
  content: ''; position: absolute; left: 30px; top: 11px; width: 44px; height: 22px;
  background: repeating-linear-gradient(transparent 0 4px, rgba(60, 50, 70, 0.5) 4px 5.5px);
  -webkit-mask: linear-gradient(90deg, #000 60%, transparent); mask: linear-gradient(90deg, #000 60%, transparent);
}
.story__kicker { margin: 0 0 0.55em; line-height: 1; display: flex; align-items: center; gap: 10px; }
.story__no { margin-left: auto; margin-right: 46px; white-space: nowrap; font-family: var(--sans); font-size: 0.72rem; letter-spacing: 0.14em; color: var(--ink-faint); }
.stamp {
  display: inline-block; padding: 0.32em 0.6em 0.26em; border: 2px solid currentColor; border-radius: 3px;
  font-family: var(--sans); font-weight: 600; font-size: 0.7rem; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--green); filter: url(#stamp); transform: rotate(-2.5deg); opacity: 0.95; mix-blend-mode: multiply;
}
.story__title { position: relative; margin: 0 0 0.45em; padding-right: 30px; font-family: var(--script); font-weight: 400; font-size: 2.55rem; line-height: 1.02; color: var(--ink); }
.story__title::after {
  content: ''; position: absolute; left: -28px; right: -28px; bottom: -0.12em; height: 1.5px;
  background: rgba(168, 53, 45, 0.42); mix-blend-mode: multiply;
}
.story__text {
  --lh: 1.6rem;
  margin: 0; font-size: 1.16rem; line-height: var(--lh); color: var(--ink-soft);
  background: repeating-linear-gradient(transparent 0 calc(var(--lh) - 1px), rgba(130, 100, 70, 0.2) calc(var(--lh) - 1px) var(--lh));
  background-position: 0 -0.28rem;
}
.story__text b { color: var(--red-ink); font-weight: 400; }
.story__text q { font-style: italic; }
.story__card::after {
  content: ''; position: absolute; right: 0; bottom: 0; width: 26px; height: 26px; pointer-events: none;
  background: linear-gradient(315deg, rgba(36, 25, 18, 0) 48%, rgba(120, 95, 70, 0.22) 50%, rgba(255, 255, 255, 0.35) 58%, rgba(0, 0, 0, 0) 75%);
}
.story__extra:empty { display: none; }
.story__extra { margin-top: 16px; display: flex; flex-wrap: wrap; gap: 10px 12px; align-items: center; }

.count { display: inline-flex; gap: 8px; }
.count span {
  display: flex; flex-direction: column; align-items: center; min-width: 50px; padding: 6px 6px 4px;
  background-color: var(--paper-2); background-image: var(--tex); background-size: 200px; background-blend-mode: multiply;
  filter: var(--shadow-sm); transform: rotate(-2deg);
}
.count span:nth-child(2) { transform: rotate(1.5deg); }
.count span:nth-child(3) { transform: rotate(-0.5deg); }
.count b { font-family: var(--hand); font-weight: 400; font-size: 1.6rem; line-height: 1; color: var(--red-ink); font-variant-numeric: tabular-nums; }
.count small { font-size: 0.82rem; color: var(--ink-soft); }

/* điều hướng: hai nút + một dây đèn nhỏ, mỗi bóng là một chương, bóng đang xem sáng lên */
.story__nav { display: flex; align-items: center; gap: 12px; }
.nav-btn {
  width: 50px; height: 50px; flex: none; border-radius: 50%; border: 0; padding: 0; display: grid; place-items: center;
  box-shadow: inset 0 0 0 2px rgba(255, 255, 255, 0.18), inset 0 -3px 6px rgba(80, 50, 20, 0.18);
  filter: var(--shadow-sm) var(--lamp);
  transition: transform 0.2s;
}
.nav-btn:hover { transform: rotate(-6deg) scale(1.05); }
.nav-btn svg { width: 24px; height: 24px; }
.nav-btn--next svg { stroke: var(--cream); }
.nav-btn:disabled { opacity: 0.4; cursor: default; transform: none; }
.story__dots {
  position: relative; list-style: none; display: flex; gap: 4px; margin: 0; padding: 0; flex: 1;
  justify-content: space-between; align-items: flex-start; height: 30px;
}
.story__dots::before {
  content: ''; position: absolute; left: -8px; right: -8px; top: 4px; height: 14px;
  background: radial-gradient(120% 140% at 50% -40%, transparent 62%, #2d3a2b 63% 72%, transparent 73%) 0 0 / calc(100% / 6) 100% repeat-x;
  filter: drop-shadow(-1px 2px 1.5px rgba(30, 16, 4, 0.35));
}
.story__dots li { position: relative; display: grid; place-items: center; padding-top: 9px; }
.story__dots li:nth-child(2n) { padding-top: 13px; }
.story__dots button {
  position: relative; width: 8px; height: 11px; padding: 0; border: 0; display: block; border-radius: 50% 50% 45% 45% / 60% 60% 40% 40%;
  background: radial-gradient(circle at 40% 35%, #fff6dc 0 20%, #e6cfa0 45%, #b39260 100%);
  box-shadow: 0 1px 2px rgba(40, 20, 6, 0.35);
  transition: transform 0.3s, box-shadow 0.4s, background 0.4s;
}
.story__dots button::before {
  content: ''; position: absolute; left: 50%; top: -4px; width: 4px; height: 4px; margin-left: -2px; border-radius: 1px; background: #2d3a2b;
}
.story__dots button[aria-current="step"] {
  background: radial-gradient(circle at 45% 40%, #fffbe8 0 25%, #ffd27a 50%, #f0902e 100%);
  box-shadow: 0 0 6px 2px rgba(255, 186, 90, 0.85), 0 0 16px 5px rgba(255, 150, 60, 0.4);
  transform: scale(1.35);
}
.story__dots button:hover { transform: scale(1.25); }
.story__modes { display: flex; gap: 12px; padding-left: 4px; }

/* ---------- khám phá ---------- */
.free-bar {
  position: fixed; left: 50%; bottom: calc(24px + var(--safe-b)); z-index: 10;
  display: flex; align-items: center; gap: 16px; padding: 10px 12px 10px 20px; border-radius: 2px;
  font-size: 1.08rem; color: var(--ink-soft); white-space: nowrap;
  filter: var(--shadow) var(--lamp);
  transform: translateX(-50%) rotate(-0.8deg);
}
.hover-label {
  position: fixed; z-index: 11; pointer-events: none; padding: 5px 13px 4px 22px; font-size: 1.05rem; color: var(--ink);
  clip-path: polygon(10px 0, 100% 0, 100% 100%, 10px 100%, 0 50%);
  filter: var(--shadow-sm);
  opacity: 0; transform: translate(-50%, -140%) rotate(-2deg) scale(0.95); transition: opacity 0.18s, transform 0.18s; white-space: nowrap;
}
.hover-label.is-on { opacity: 1; transform: translate(-50%, -155%) rotate(-2deg) scale(1); }

/* ---------- thiệp 3D ---------- */
.inv-actions {
  position: fixed; z-index: 12; left: 50%; bottom: calc(20px + var(--safe-b)); transform: translateX(-50%);
  display: flex; gap: 10px 12px; flex-wrap: wrap; justify-content: center; width: min(780px, calc(100vw - 24px));
  animation: rise 0.5s ease both;
}
.inv-actions .btn--ghost { color: var(--cream); border-color: rgba(255, 240, 220, 0.6); text-shadow: 0 1px 3px rgba(0, 0, 0, 0.5); }
.inv-hint { position: fixed; z-index: 12; top: 78px; left: 50%; transform: translateX(-50%); margin: 0; font-size: 1.05rem; color: var(--cream); text-shadow: 0 1px 6px rgba(0, 0, 0, 0.6); }

/* ---------- hộp thoại ---------- */
.modal { position: fixed; inset: 0; z-index: 40; display: grid; place-items: center; padding: 16px; background: rgba(28, 16, 8, 0.5); backdrop-filter: blur(3px); -webkit-backdrop-filter: blur(3px); animation: fade 0.25s ease both; }
@keyframes fade { from { opacity: 0; } }
.modal__box {
  position: relative; width: min(520px, 100%); max-height: calc(100dvh - 32px); overflow: auto; border-radius: 3px;
  padding: 34px 30px 26px; color: var(--ink);
  filter: var(--shadow);
  animation: drop 0.45s cubic-bezier(.2, .9, .3, 1.15) both;
}
.modal__box--card { box-shadow: inset 0 3px 0 rgba(168, 53, 45, 0.85); }
@keyframes drop { from { opacity: 0; transform: translateY(18px) rotate(-2.5deg); } }
.modal__box--narrow { width: min(400px, 100%); }
.modal__box--album { width: min(1000px, 100%); background-color: #3a2c22; color: var(--cream); }
.modal__box--album h2 { color: var(--cream); }
.modal__box--album .modal__x { color: var(--cream); }
.modal__box h2 { font-family: var(--script); font-weight: 400; font-size: 2.6rem; line-height: 1; margin: 0 0 0.35em; }
.modal__box h3 { font-family: var(--script); font-weight: 400; font-size: 1.9rem; margin: 1em 0 0.2em; }
.modal__box p, .modal__box li { line-height: 1.55; font-size: 1.08rem; color: var(--ink-soft); }
.modal__lead { margin-top: 0; }
.modal__x { position: absolute; top: 12px; right: 12px; width: 36px; height: 36px; border: 0; background: none; font-family: var(--hand); font-size: 1.4rem; color: var(--ink-soft); }
.credits { padding-left: 1.1em; }
.credits code { font-size: 0.85em; background: rgba(0, 0, 0, 0.06); padding: 0 4px; border-radius: 3px; }

.seg { display: flex; gap: 10px; margin-bottom: 16px; flex-wrap: wrap; }
.seg label { flex: 1; min-width: 150px; }
.seg input { position: absolute; opacity: 0; }
.seg span { display: block; text-align: center; padding: 0.55em; font-size: 1.08rem; cursor: pointer; color: var(--ink-soft); border: 1.5px dashed rgba(85, 67, 47, 0.4); border-radius: 3px; }
.seg input:checked + span {
  color: var(--cream); border: 1.5px solid transparent;
  background-color: var(--red); background-image: var(--tex); background-size: 220px; background-blend-mode: multiply;
  filter: var(--shadow-sm); transform: rotate(-1deg);
}
.seg input:focus-visible + span { outline: 2px solid var(--red); outline-offset: 2px; }
.field { display: flex; flex-direction: column; gap: 2px; margin-bottom: 12px; flex: 1; }
.field span { font-size: 1.02rem; color: var(--ink-soft); }
.field input, .field select, .field textarea {
  font: 500 0.95rem var(--sans); color: var(--ink); background: transparent;
  border: 0; border-bottom: 1.5px solid rgba(85, 67, 47, 0.35); border-radius: 0; padding: 0.45em 0.1em;
}
.field input::placeholder { color: var(--ink-faint); font-weight: 400; }
.field select { cursor: pointer; }
.field textarea {
  resize: vertical; border: 0; line-height: 1.6rem; padding: 0.2em 0.1em;
  background: repeating-linear-gradient(transparent 0 calc(1.6rem - 1px), rgba(92, 128, 170, 0.25) calc(1.6rem - 1px) 1.6rem);
}
.field input:focus, .field select:focus, .field textarea:focus { outline: none; border-color: var(--red); }
.row { display: flex; gap: 14px; }
.form-note { font-size: 0.98rem; min-height: 1.2em; margin: 0.6em 0 0; }

.toc { list-style: none; padding: 0; margin: 0; counter-reset: c; }
.toc li { counter-increment: c; }
.toc button {
  width: 100%; text-align: left; border: 0; background: none; padding: 0.4em 0.2em; display: flex; gap: 0.8em; align-items: baseline;
  color: var(--ink); font-size: 1.1rem; border-bottom: 1px solid rgba(92, 128, 170, 0.2);
}
.toc button::before { content: counter(c, decimal-leading-zero); font-size: 0.85rem; color: var(--red-ink); }
.toc button small { margin-left: auto; color: var(--ink-faint); font-size: 0.85rem; white-space: nowrap; }
.toc button:hover { color: var(--red-ink); }

/* album: cuộn phim polaroid trên nền bàn gỗ tối */
.album { display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 20px; margin-top: 10px; }
.album figure {
  margin: 0; padding: 10px 10px 14px; color: var(--ink);
  background-color: #fbf7ef; background-image: var(--tex); background-size: 220px; background-blend-mode: multiply;
  filter: var(--shadow); transform: rotate(var(--r, 0deg));
}
.album img { width: 100%; aspect-ratio: 4 / 5; object-fit: cover; display: block; }
.album figcaption { font-family: var(--hand); font-size: 1.05rem; margin-top: 8px; line-height: 1.3; text-align: center; }

.toast {
  position: fixed; z-index: 45; left: 50%; top: 80px; opacity: 0; pointer-events: none;
  color: var(--ink); padding: 14px 20px 12px; border-radius: 2px; font-size: 1.08rem; line-height: 1.5;
  max-width: min(440px, calc(100vw - 32px)); text-align: center;
  filter: var(--shadow) var(--lamp);
  transform: translate(-50%, -12px) rotate(-1.5deg); transition: opacity 0.25s, transform 0.3s;
}
.toast::before {
  content: ''; position: absolute; top: -11px; left: 50%; width: 80px; height: 22px; margin-left: -40px; transform: rotate(3deg);
  background: repeating-linear-gradient(-45deg, rgba(255, 255, 255, 0.3) 0 5px, rgba(255, 255, 255, 0) 5px 11px), rgba(160, 196, 170, 0.8);
  clip-path: polygon(3% 0, 97% 0, 100% 20%, 97% 45%, 100% 70%, 97% 100%, 3% 100%, 0 75%, 3% 50%, 0 25%);
  mix-blend-mode: multiply;
}
.toast.is-on { opacity: 1; transform: translate(-50%, 0) rotate(-1.5deg); }
.toast b { color: var(--red-ink); font-weight: 400; }

.noscript { position: fixed; inset: 0; display: grid; place-items: center; color: var(--cream); }

/* ---------- điện thoại dọc: thẻ nằm dưới đáy ---------- */
@media (max-aspect-ratio: 1/1) {
  .story { left: 14px; right: 14px; width: auto; bottom: calc(10px + var(--safe-b)); gap: 10px; }
  .story__card { padding: 22px 20px 16px; }
  .story__title { font-size: 2.1rem; }
  .story__title::after { left: -20px; right: -20px; }
  .story__text { --lh: 1.45rem; font-size: 1.04rem; background-position: 0 -0.25rem; }
  .story__extra { margin-top: 12px; }
  .story__modes { position: fixed; top: 74px; right: 14px; flex-direction: column; align-items: flex-end; gap: 10px; }
  .story.is-hidden .story__modes { opacity: 0; }
  body[data-ch="giua"] .story__modes { display: none; }   /* điện thoại: chỉ hiện ở chương đầu và cuối */
  .story__nav { padding-right: 58px; }   /* chừa chỗ nút nhạc chung góc dưới phải */
  .nav-btn { width: 44px; height: 44px; }
  .brand__names { font-size: 1.55rem; }
  .brand { left: 12px; top: 12px; padding: 5px 11px 4px; }
  .icon-btn { width: 38px; height: 38px; }
  .icon-btn svg { width: 19px; height: 19px; }
  .tools { gap: 11px; right: 14px; top: 16px; }
  .inv-actions { bottom: calc(70px + var(--safe-b)); }
  .inv-actions .btn { padding: 0.5em 0.9em 0.45em; font-size: 0.98rem; }
  .free-bar { font-size: 0.98rem; }
}
@media (max-width: 380px) {
  .story__text { --lh: 1.38rem; font-size: 0.98rem; }
  .story__title { font-size: 1.9rem; }
}
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01s !important; transition-duration: 0.01s !important; }
}